The CompressionMethod property is a free form string indicating the algorithm or tool used to compress the logical file. ...

The CompressionMethod property is a free form string indicating the algorithm or tool used to compress the logical file. If it is not possible (or not desired) to describe the compression scheme (perhaps because it is not known), use the following words: \"Unknown\" to represent that it is not known whether the logical file is compressed or not, \"Compressed\" to represent that the file is compressed but either its compression scheme is not known or not disclosed, and \"Not Compressed\" to represent that the logical file is not compressed.